A climate article not about CO2
Find out why methane stinks and laughing gas is not funny, and who are working to resolve this.
The “greenhouse effect” is caused by a family of gases that absorb and emit infrared energy from the atmosphere down to the earth’s surface, which is a fancy way of saying they act as Earth’s blanket. This blanket matters a lot, and without it, Earth’s average temperature would be -18 °C (-0.4 °F for my American readers). By burning fossil fuels, we are putting on too many blankets and amplifying earths warming effects, resulting in a rise in environmental disasters and a change in Earth’s average climate.
Right now, most of the current attention is given to CO2, and language like “carbon neutral” and “zero-carbon” is often being incorrectly used as a proxy for "net zero,” which has had the unintended consequence of directing attention away from some of the most cost-effective abatement options for reducing non-CO2 greenhouse gas (OGHG) emissions. To stop at 1.5 °C of warming, all the feasible pathways show that a significant reduction in the other greenhouse gases is required. Let’s meet them.
Who are they?
Methane
Methane accounts for about 30% of the increase in the global temperature since industrialisation, and emissions reached new highs for the second year in a row last year. Significant reductions in methane emissions are required in order to slow climate change, with the UN targeting a 30% reduction in emissions by 2030. Despite having a much shorter lifetime in the atmosphere than CO2, methane is much more effective at trapping heat, and over a 20-year period, it is ~80 times more potent. Methane is released into the atmosphere through a combination of natural processes and human-caused activities. Human activity produces methane in three major sectors: agriculture (40%), fossil fuels (35%), and waste (20%). Within these sectors, the most prominent emitters are livestock farming (cow burps), the processing and distribution of fossil fuels (gas leaks), coal mining, tillage, landfills, and wastewater management.
Methane emissions are difficult to measure due to the spatial and temporal variability of their sources. What this means is that when companies track their methane emissions, they use inventory-based estimates as opposed to actual, measured emissions. This is often misleading and leads firms to optimise for perceived emissions in an inventory, which is often not a good proxy for actual emissions and stifles the incentives for targeting methane-reducing innovations. The data gap prevents regulation from effectively creating a financial incentive to reduce methane emissions, and consumers are not incentivised to fully take into account their methane footprint, bar the infrequent cow fart animation.
Who’s working on this?
Measurement -
Kuva Systems (gas cloud imaging), Orbio Earth (asset level satellite data solutions), LongPath Technologies (Nobel Prize-winning methane leak detection capabilities), LoCI Controls (landfill gas collections data collector)
Agriculture -
ArkeaBio (vaccine for cows to reduce emissions) Rumin8, FutureFeed, Seaforest, Fremantle Seaweed, Volta Greentech, Symbrosia (using seaweed to reduce emissions from cow burps), ZELP (masks for cows)
Waste -
Vespene Energy (methane capture from landfills and energy generation), Waga Energy (waste valorisation to produce biomethane)
Nitrous Oxide
"Laughing gas", also known as nitrous oxide, is not only a tool used by dentists to sedate patients, or a recreational drug used at raves, but it is a powerful greenhouse gas. Despite its low abundance in the atmosphere, nitrous oxide is nearly 300 times more effective at trapping heat than CO2. N2O also lives longer in the atmosphere than methane, warming our climate as long as between 1 and 2 centuries. Alongside its warming effect, it damages the Ozone layer, as while it sits in the stratosphere with oxygen and sunlight, it reacts to become nitrous oxides.
Sharing many sources in common with methane, anthropogenic sources of N2O include agriculture (e.g. fertiliser use), industrial processes (e.g. nylon production), and the combustion of fossil fuels. Emissions from agriculture are greatest, and in the US, about 75% of all N2O emissions from human activity are attributed to agriculture. With the global population forecasted to grow to 10 billion by 2050, we will have many more mouths to feed, and in order to meet this ramp up in demand, fertiliser use and production will need to be ramped up.
Who’s working on this?
Measurement -
Cobalt Water Global (ML platform for water utilities), Northeastern university (project to develop a nitrous oxide detecting robot)
Agriculture -
Pastoral Robotics, Sound Ag, Indigo Ag (Reduce fertiliser application),
Industrial processes -
Geno (Green nylon), TOPSOE (reducing N2O emissions from nitric acid production)
Fluorinated gases
Fluorinated gases, also known as hydrofluorocarbons (HFCs), are a class of man-made gases with a high potential for global warming and contribute to climate change. As a ‘family’ of gases, their potency differs, but in general they are 1,000-10,000 times as powerful as CO2. Like nitrous oxide, these can damage the Ozone layer, but since the Montreal Protocol in 1987, these emissions have been reduced much more relative to the other GHGs. HFCs are used in a variety of applications, including refrigeration and air conditioning, foam insulation, and as solvents.
Who’s working on this?
Air conditioning -
Blue Frontier (more efficient cooling and refrigeration) Energy Solaris (replaces rooftop ventilation systems), Dynamic Air Cooling (no HFC refrigeration), Triple Solar (solar panels which cool)
What does the future hold?
The aforementioned technologies will be vital in reduction of OGHGs, and it is ever more important to innovate in this space. Due to the difficulty in atmospheric removal of these gases, the most promising solutions are likely to be those that target efficiency improvements, are low-emitting alternatives, improve measurement, and those that capture at the source of these emissions.
Even now, without immediate technological innovation, reducing these emissions are widely seen to be the cheapest and best way of targeting net zero in the short term, especially with methane. For example, with pre-existing technology, a 75% reduction in methane from the oil and gas sector is possible, and 50% of this could be done at no net cost.
As the world is paying more and more attention to limiting warming, those that seek to limit their true environmental impact will ultimately be those who succeed. Even now, large corporates are starting to set methane specific targets, with Danone, a company who works directly with 58,000 dairy farmers, recently announcing a target of a 30% reduction in methane emissions. Those who decide to pursue targets of these OGHG’s early will be better prepared once the data and measurement capabilities are developed and widely adopted, and given the salient role of OGHG’s in causing short-term warming, it is only a matter of time.
Cutting methane emissions is the best way to slow climate change over the next 25 years.
Inger Andersen, Executive Director, UNEP